# YOLOv5 🚀 by Ultralytics, GPL-3.0 license
"""
Compress a YOLOv5 model on a custom dataset

Usage:
    $ python path/to/compress.py --data coco.yaml --weights yolov5s.pt --img 640
"""

import argparse
import logging
import math
import os
import sys
import time
from pathlib import Path

import torch.distributed as dist
import torch.nn as nn
import yaml
from torch.cuda import amp
from torch.nn.parallel import DistributedDataParallel as DDP
from torch.optim import Adam, SGD, lr_scheduler
from tqdm import tqdm
import random

FILE = Path(__file__).resolve()
ROOT = FILE.parents[0]  # YOLOv5 root directory
if str(ROOT) not in sys.path:
    sys.path.append(str(ROOT))  # add ROOT to PATH

import val  # for end-of-epoch mAP
from models.experimental import attempt_load
from models.yolo import Model
from utils.autoanchor import check_anchors
from utils.dataloaders import create_dataloader
from utils.general import labels_to_class_weights, increment_path, labels_to_image_weights, init_seeds, \
    strip_optimizer, get_latest_run, check_dataset, check_git_status, check_img_size, check_requirements, \
    check_file, check_yaml, check_suffix, print_args, set_logging, one_cycle, colorstr, methods
from utils.downloads import attempt_download
from utils.plots import plot_labels
from utils.torch_utils import EarlyStopping, ModelEMA, de_parallel, select_device, \
    torch_distributed_zero_first
from utils.general import intersect_dicts
from utils.metrics import fitness
from utils.loggers import Loggers
from utils.callbacks import Callbacks
from prune import *

LOGGER = logging.getLogger(__name__)
LOCAL_RANK = int(os.getenv('LOCAL_RANK', -1))  # https://pytorch.org/docs/stable/elastic/run.html
RANK = int(os.getenv('RANK', -1))
WORLD_SIZE = int(os.getenv('WORLD_SIZE', 1))
logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(message)s')


def compress(model, dataloader, args):
    """
    the implementation of model compression. Currently correlation, l1, l2 algorithms are supported.
    :param model: the model to be compressed
    :param dataloader: the dataset for the evaluation of the model performance
    :param args: the compression argument dictionary
    :return: the pruned model
    """
    compress_savedir = args.save_dir + '/compression'
    model_name = args.model.lower()
    dataset_name = args.dataset.lower()
    compression_body = args.compression.lower()
    compresion_method = args.prunemethod.lower()
    round = args.round
    topk = args.topk
    exp = args.exp
    imgsz = args.imgsz

    if not os.path.exists(compress_savedir):
        os.makedirs(compress_savedir)
    model_path = os.path.join(compress_savedir, f'pruned_{model_name}_{imgsz}_{compression_body}_{dataset_name}_r{round}.pkl')

    if os.path.exists(model_path):
        pruned_model = torch.load(model_path)
    else:
        LOGGER.info('Start Pruning...')

        '''Initialize the sensitivity computation of the model'''
        sens = Sensitivity(.05, .95, 19, compresion_method, round, exp, topk, args, LOGGER)
        sen_dict = sens(model, dataloader, args.part)
        LOGGER.info('sensitivity:' + str(sen_dict))
        rate = sens.get_ratio(sen_dict)
        LOGGER.info('rate: ' + str(rate))
        pruned_model = deepcopy(model)
        strategy = tp.strategy.L1Strategy() if compresion_method == 'l1' else tp.strategy.L2Strategy()
        DG = DependencyGraph()
        DG.build_dependency(pruned_model, example_inputs=torch.randn(1, 3, imgsz, imgsz))

        start_time = time.time()
        for i, k in enumerate(rate.keys()):
            if 'group' in k:
                group_id = int(k[5:])
                group = sens.groups[group_id - 1]
                to_prune_list = group_l1prune(pruned_model, group, rate[k], round_to=1)
                layers = eval(
                    f'pruned_model.module.{group[0]} if hasattr(pruned_model, "module") else pruned_model.{group[0]}')
            else:
                layers = eval(f'pruned_model.module.{k} if hasattr(pruned_model, "module") else pruned_model.{k}')
                to_prune_list = strategy(layers.weight, amount=rate[k], round_to=1)
            if isinstance(layers, torch.nn.Conv2d):
                prune_m = tp.prune_conv
            pruning_plan = DG.get_pruning_plan(layers, prune_m, idxs=to_prune_list)
            pruning_plan.exec()

        LOGGER.info(f'prune duration: {time.time() - start_time}')
        torch.save(pruned_model, os.path.join(compress_savedir,
                                              f'pruned_{model_name}_{imgsz}_{compression_body}_{dataset_name}_r{round}.pkl'))
        del sens, sen_dict
        gc.collect()
    return pruned_model


def train(hyp,  # path/to/hyp.yaml or hyp dictionary
          opt,
          device,
          callbacks
          ):
    save_dir, epochs, batch_size, weights, single_cls, evolve, data, cfg, resume, noval, nosave, workers, freeze, compress_round = \
        Path(opt.save_dir), opt.epochs, opt.batch_size, opt.weights, opt.single_cls, opt.evolve, opt.data, opt.cfg, \
        opt.resume, opt.noval, opt.nosave, opt.workers, opt.freeze, opt.round

    # Directories
    w = save_dir / 'weights'  # weights dir
    (w.parent if evolve else w).mkdir(parents=True, exist_ok=True)  # make dir
    last, best = w / 'last.pt', w / 'best.pt'
    handler = logging.FileHandler(f"{save_dir}/log.txt")
    handler.setLevel(logging.INFO)
    formatter = logging.Formatter('%(asctime)s- %(message)s')
    handler.setFormatter(formatter)
    LOGGER.addHandler(handler)

    # Hyperparameters
    if isinstance(hyp, str):
        with open(hyp) as f:
            hyp = yaml.safe_load(f)  # load hyps dict
    LOGGER.info(colorstr('hyperparameters: ') + ', '.join(f'{k}={v}' for k, v in hyp.items()))

    # Save run settings
    with open(save_dir / 'hyp.yaml', 'w') as f:
        yaml.safe_dump(hyp, f, sort_keys=False)
    with open(save_dir / 'opt.yaml', 'w') as f:
        yaml.safe_dump(vars(opt), f, sort_keys=False)
    data_dict = None

    # Loggers
    if RANK in [-1, 0]:
        loggers = Loggers(save_dir, weights, opt, hyp, LOGGER)  # loggers instance
        if resume:
            weights, epochs, hyp = opt.weights, opt.epochs, opt.hyp

        # Register actions
        for k in methods(loggers):
            callbacks.register_action(k, callback=getattr(loggers, k))

    # Config
    plots = not evolve  # create plots
    cuda = device.type != 'cpu'
    init_seeds(1 + RANK)
    with torch_distributed_zero_first(RANK):
        data_dict = data_dict or check_dataset(data)  # check if None
    train_path, val_path = data_dict['train'], data_dict['val']
    nc = 1 if single_cls else int(data_dict['nc'])  # number of classes
    names = ['item'] if single_cls and len(data_dict['names']) != 1 else data_dict['names']  # class names
    assert len(names) == nc, f'{len(names)} names found for nc={nc} dataset in {data}'  # check
    is_coco = data.endswith('coco.yaml') and nc == 80  # COCO dataset

    # Model
    check_suffix(weights, ['.pt', '.pkl'])  # check weights
    pretrained = weights.endswith('.pt')
    if pretrained:
        with torch_distributed_zero_first(RANK):
            weights = attempt_download(weights)  # download if not found locally
        ckpt = torch.load(weights, map_location=device)  # load checkpoint
        model = Model(cfg or ckpt['model'].yaml, ch=3, nc=nc, anchors=hyp.get('anchors')).to(device)  # create
        exclude = ['anchor'] if (cfg or hyp.get('anchors')) and not resume else []  # exclude keys
        csd = ckpt['model'].float().state_dict()  # checkpoint state_dict as FP32
        csd = intersect_dicts(csd, model.state_dict(), exclude=exclude)  # intersect
        model.load_state_dict(csd, strict=False)  # load
        LOGGER.info(f'Transferred {len(csd)}/{len(model.state_dict())} items from {weights}')  # report
    elif weights.endswith('.pkl'):
        model = torch.load(weights, map_location=device)
        for p in model.parameters():
            p.requires_grad_(True)
        model.info(img_size=opt.imgsz)
        LOGGER.info(f'Loaded {weights}')
    else:
        model = Model(cfg, ch=3, nc=nc, anchors=hyp.get('anchors')).to(device)  # create


    # Image sizes
    gs = max(int(model.stride.max()), 32)  # grid size (max stride)
    nl = model.model[-1].nl  # number of detection layers (used for scaling hyp['obj'])
    imgsz = check_img_size(opt.imgsz, gs, floor=gs * 2)  # verify imgsz is gs-multiple

    # Trainloader
    train_loader, dataset = create_dataloader(train_path, imgsz, batch_size // WORLD_SIZE, gs, single_cls,
                                              hyp=hyp, augment=True, cache=opt.cache, rect=opt.rect, rank=RANK,
                                              workers=workers, image_weights=opt.image_weights, quad=opt.quad,
                                              prefix=colorstr('train: '))
    labels = np.concatenate(dataset.labels, 0)
    mlc = int(np.concatenate(dataset.labels, 0)[:, 0].max())  # max label class
    nb = len(train_loader)  # number of batches
    assert mlc < nc, f'Label class {mlc} exceeds nc={nc} in {data}. Possible class labels are 0-{nc - 1}'


    # Process 0
    if RANK in [-1, 0]:
        val_loader = create_dataloader(val_path, imgsz, batch_size // WORLD_SIZE * 2, gs, single_cls,
                                       hyp=hyp, cache=None if noval else opt.cache, rect=True, rank=-1,
                                       workers=workers, pad=0.5,
                                       prefix=colorstr('val: '))[0]

        if not resume:
            labels = np.concatenate(dataset.labels, 0)
            # c = torch.tensor(labels[:, 0])  # classes
            # cf = torch.bincount(c.long(), minlength=nc) + 1.  # frequency
            # model._initialize_biases(cf.to(device))
            if plots:
                plot_labels(labels, names, save_dir)

            # Anchors
            if not opt.noautoanchor:
                check_anchors(dataset, model=model, thr=hyp['anchor_t'], imgsz=imgsz)
            model.half().float()  # pre-reduce anchor precision

        callbacks.run('on_pretrain_routine_end', labels, names)

    # Start compressing the model
    if not opt.pruned:
        # Model parameters
        hyp['box'] *= 3. / nl  # scale to layers
        hyp['cls'] *= nc / 80. * 3. / nl  # scale to classes and layers
        hyp['obj'] *= (imgsz / 640) ** 2 * 3. / nl  # scale to image size and layers
        hyp['label_smoothing'] = opt.label_smoothing
        model.nc = nc  # attach number of classes to model
        model.hyp = hyp  # attach hyperparameters to model
        model.class_weights = labels_to_class_weights(dataset.labels, nc).to(device) * nc  # attach class weights
        model.names = names
        if RANK in [-1, 0]:
            LOGGER.info('Compressing the model...')

        with torch_distributed_zero_first(RANK):
            pruned_model = compress(model, val_loader if RANK in [-1, 0] else None, opt)
        pruned_model = pruned_model.to(device)
    else:
        assert os.path.exists(opt.pruned_model)
        pruned_model = torch.load(opt.pruned_model)
        pruned_model = pruned_model.to(device)
        compress_savedir = save_dir / 'compression'
        if not os.path.exists(compress_savedir):
            os.makedirs(compress_savedir)

    n_p_ori, _, fs_ori = model.cuda().info(False, img_size=imgsz)
    n_p_pruned, _, fs_pruned = pruned_model.cuda().info(True, img_size=imgsz)
    p_rate = n_p_pruned / n_p_ori
    fs_rate = fs_pruned / fs_ori
    if RANK in [-1, 0]:
        LOGGER.info(f'round {compress_round}: parameter rate {p_rate * 100:.4f}, FLOPs rate {fs_rate * 100:.4f}')

    del model
    gc.collect()

    # Freeze
    freeze = [f'model.{x}.' for x in range(freeze)]  # layers to freeze
    for k, v in pruned_model.named_parameters():
        v.requires_grad = True  # train all layers
        if any(x in k for x in freeze):
            print(f'freezing {k}')
            v.requires_grad = False

    # Optimizer
    nbs = 64  # nominal batch size
    accumulate = max(round(nbs / batch_size), 1)  # accumulate loss before optimizing
    hyp['weight_decay'] *= batch_size * accumulate / nbs  # scale weight_decay
    LOGGER.info(f"Scaled weight_decay = {hyp['weight_decay']}")

    g0, g1, g2 = [], [], []  # optimizer parameter groups
    for v in pruned_model.modules():
        if hasattr(v, 'bias') and isinstance(v.bias, nn.Parameter):  # bias
            g2.append(v.bias)
        if isinstance(v, nn.BatchNorm2d):  # weight (no decay)
            g0.append(v.weight)
        elif hasattr(v, 'weight') and isinstance(v.weight, nn.Parameter):  # weight (with decay)
            g1.append(v.weight)

    optimizer = SGD(g0, lr=hyp['lr0'], momentum=hyp['momentum'], nesterov=True)

    optimizer.add_param_group({'params': g1, 'weight_decay': hyp['weight_decay']})  # add g1 with weight_decay
    optimizer.add_param_group({'params': g2})  # add g2 (biases)
    LOGGER.info(f"{colorstr('optimizer:')} {type(optimizer).__name__} with parameter groups "
                f"{len(g0)} weight, {len(g1)} weight (no decay), {len(g2)} bias")
    del g0, g1, g2

    # Scheduler
    lf = one_cycle(1, hyp['lrf'], epochs)  # cosine 1->hyp['lrf']
    scheduler = lr_scheduler.LambdaLR(optimizer, lr_lambda=lf)  # plot_lr_scheduler(optimizer, scheduler, epochs)

    # EMA
    ema = ModelEMA(pruned_model) if RANK in [-1, 0] else None

    start_epoch, best_fitness = 0, 0.0
    if cuda and RANK == -1 and torch.cuda.device_count() > 1:
        logging.warning('DP not recommended, instead use torch.distributed.run for best DDP Multi-GPU results.\n'
                        'See Multi-GPU Tutorial at https://github.com/ultralytics/yolov5/issues/475 to get started.')
        pruned_model = torch.nn.DataParallel(pruned_model)

    # SyncBatchNorm
    if opt.sync_bn and cuda and RANK != -1:
        pruned_model = torch.nn.SyncBatchNorm.convert_sync_batchnorm(pruned_model).to(device)
        LOGGER.info('Using SyncBatchNorm()')

    # DDP mode
    if cuda and RANK != -1:
        pruned_model = DDP(pruned_model, device_ids=[LOCAL_RANK], output_device=LOCAL_RANK)

    # Model parameters
    hyp['box'] *= 3. / nl  # scale to layers
    hyp['cls'] *= nc / 80. * 3. / nl  # scale to classes and layers
    hyp['obj'] *= (imgsz / 640) ** 2 * 3. / nl  # scale to image size and layers
    hyp['label_smoothing'] = opt.label_smoothing
    pruned_model.nc = nc  # attach number of classes to model
    pruned_model.hyp = hyp  # attach hyperparameters to model
    pruned_model.class_weights = labels_to_class_weights(dataset.labels, nc).to(device) * nc  # attach class weights
    pruned_model.names = names

    # Start training
    t0 = time.time()
    nw = max(round(hyp['warmup_epochs'] * nb), 1000)  # number of warmup iterations, max(3 epochs, 1k iterations)
    # nw = min(nw, (epochs - start_epoch) / 2 * nb)  # limit warmup to < 1/2 of training
    last_opt_step = -1
    maps = np.zeros(nc)  # mAP per class
    results = (0, 0, 0, 0, 0, 0, 0)  # P, R, mAP@.5, mAP@.5-.95, val_loss(box, obj, cls)
    scheduler.last_epoch = start_epoch - 1  # do not move
    scaler = amp.GradScaler(enabled=cuda)
    stopper = EarlyStopping(patience=opt.patience)
    compute_loss = ComputeLoss(pruned_model)  # init loss class
    LOGGER.info(f'Image sizes {imgsz} train, {imgsz} val\n'
                f'Using {train_loader.num_workers} dataloader workers\n'
                f"Logging results to {colorstr('bold', save_dir)}\n"
                f'Starting training for {epochs} epochs...')
    for epoch in range(start_epoch, epochs):  # epoch ------------------------------------------------------------------
        pruned_model.train()

        # Update image weights (optional, single-GPU only)
        if opt.image_weights:
            cw = pruned_model.class_weights.cpu().numpy() * (1 - maps) ** 2 / nc  # class weights
            iw = labels_to_image_weights(dataset.labels, nc=nc, class_weights=cw)  # image weights
            dataset.indices = random.choices(range(dataset.n), weights=iw, k=dataset.n)  # rand weighted idx

        mloss = torch.zeros(3, device=device)  # mean losses
        if RANK != -1:
            train_loader.sampler.set_epoch(epoch)
        pbar = enumerate(train_loader)
        LOGGER.info(('\n' + '%10s' * 7) % ('Epoch', 'gpu_mem', 'box', 'obj', 'cls', 'labels', 'img_size'))
        if RANK in [-1, 0]:
            pbar = tqdm(pbar, total=nb)  # progress bar
        optimizer.zero_grad()
        for i, (imgs, targets, paths, _) in pbar:  # batch -------------------------------------------------------------
            ni = i + nb * epoch  # number integrated batches (since train start)
            imgs = imgs.to(device, non_blocking=True).float() / 255.0  # uint8 to float32, 0-255 to 0.0-1.0

            # Warmup
            if ni <= nw:
                xi = [0, nw]  # x interp
                # compute_loss.gr = np.interp(ni, xi, [0.0, 1.0])  # iou loss ratio (obj_loss = 1.0 or iou)
                accumulate = max(1, np.interp(ni, xi, [1, nbs / batch_size]).round())
                for j, x in enumerate(optimizer.param_groups):
                    # bias lr falls from 0.1 to lr0, all other lrs rise from 0.0 to lr0
                    x['lr'] = np.interp(ni, xi, [hyp['warmup_bias_lr'] if j == 2 else 0.0, x['initial_lr'] * lf(epoch)])
                    if 'momentum' in x:
                        x['momentum'] = np.interp(ni, xi, [hyp['warmup_momentum'], hyp['momentum']])

            # Multi-scale
            if opt.multi_scale:
                sz = random.randrange(imgsz * 0.5, imgsz * 1.5 + gs) // gs * gs  # size
                sf = sz / max(imgs.shape[2:])  # scale factor
                if sf != 1:
                    ns = [math.ceil(x * sf / gs) * gs for x in imgs.shape[2:]]  # new shape (stretched to gs-multiple)
                    imgs = nn.functional.interpolate(imgs, size=ns, mode='bilinear', align_corners=False)

            # Forward
            with amp.autocast(enabled=cuda):
                pred = pruned_model(imgs)  # forward
                loss, loss_items = compute_loss(pred, targets.to(device))  # loss scaled by batch_size
                if RANK != -1:
                    loss *= WORLD_SIZE  # gradient averaged between devices in DDP mode
                if opt.quad:
                    loss *= 4.

            # Backward
            scaler.scale(loss).backward()

            # Optimize
            if ni - last_opt_step >= accumulate:
                scaler.step(optimizer)  # optimizer.step
                scaler.update()
                optimizer.zero_grad()
                if ema:
                    ema.update(pruned_model)
                last_opt_step = ni

            # Log
            if RANK in [-1, 0]:
                mloss = (mloss * i + loss_items) / (i + 1)  # update mean losses
                mem = f'{torch.cuda.memory_reserved() / 1E9 if torch.cuda.is_available() else 0:.3g}G'  # (GB)
                pbar.set_description(('%10s' * 2 + '%10.4g' * 5) % (
                    f'{epoch}/{epochs - 1}', mem, *mloss, targets.shape[0], imgs.shape[-1]))
                callbacks.run('on_train_batch_end', pruned_model, ni, imgs, targets, paths, list(mloss))
            # end batch ------------------------------------------------------------------------------------------------

        # Scheduler
        lr = [x['lr'] for x in optimizer.param_groups]  # for loggers
        scheduler.step()

        if RANK in [-1, 0]:
            # mAP
            callbacks.run('on_train_epoch_end', epoch=epoch)
            ema.update_attr(pruned_model, include=['yaml', 'nc', 'hyp', 'names', 'stride', 'class_weights'])
            final_epoch = (epoch + 1 == epochs) or stopper.possible_stop
            if not noval or final_epoch:  # Calculate mAP
                results, maps, _ = val.run(data_dict,
                                           batch_size=batch_size // WORLD_SIZE * 2,
                                           imgsz=imgsz,
                                           model=ema.ema,
                                           single_cls=single_cls,
                                           dataloader=val_loader,
                                           save_dir=save_dir,
                                           save_json=is_coco and final_epoch,
                                           verbose=nc < 50 and final_epoch,
                                           plots=plots and final_epoch,
                                           callbacks=callbacks,
                                           compute_loss=compute_loss)

            # Update best mAP
            fi = fitness(np.array(results).reshape(1, -1))  # weighted combination of [P, R, mAP@.5, mAP@.5-.95]
            if fi > best_fitness:
                best_fitness = fi
            log_vals = list(mloss) + list(results) + lr
            callbacks.run('on_fit_epoch_end', log_vals, epoch, best_fitness, fi)

            # Save model
            if (not nosave) or (final_epoch and not evolve):  # if save
                ckpt = {'epoch': epoch,
                        'best_fitness': best_fitness,
                        'model': deepcopy(de_parallel(pruned_model)).half(),
                        'ema': deepcopy(ema.ema).half(),
                        'updates': ema.updates,
                        'optimizer': optimizer.state_dict(),
                        'wandb_id': loggers.wandb.wandb_run.id if loggers.wandb else None}

                # Save last, best and delete
                torch.save(ckpt, last)
                if best_fitness == fi:
                    torch.save(ckpt, best)
                    torch.save(ema.ema, os.path.join(str(save_dir) + '/compression', 'best_model.pkl'))
                del ckpt
                callbacks.run('on_model_save', last, epoch, final_epoch, best_fitness, fi)

            # Stop Single-GPU
            if RANK == -1 and stopper(epoch=epoch, fitness=fi):
                break
        # end epoch ----------------------------------------------------------------------------------------------------
    # end training -----------------------------------------------------------------------------------------------------
    if RANK in [-1, 0]:
        LOGGER.info(f'\n{epoch - start_epoch + 1} epochs completed in {(time.time() - t0) / 3600:.3f} hours.')
        if not evolve:
            if is_coco:  # COCO dataset
                for m in [last, best] if best.exists() else [last]:  # speed, mAP tests
                    results, _, _ = val.run(data_dict,
                                            batch_size=batch_size // WORLD_SIZE * 2,
                                            imgsz=imgsz,
                                            model=attempt_load(m, device).half(),
                                            iou_thres=0.7,  # NMS IoU threshold for best pycocotools results
                                            single_cls=single_cls,
                                            dataloader=val_loader,
                                            save_dir=save_dir,
                                            save_json=True,
                                            plots=False)
            # Strip optimizers
            for f in last, best:
                if f.exists():
                    strip_optimizer(f)  # strip optimizers
        callbacks.run('on_train_end', last, best, plots, epoch)
        LOGGER.info(f"Results saved to {colorstr('bold', save_dir)}")

    torch.cuda.empty_cache()
    return results


def parse_opt(known=False):
    parser = argparse.ArgumentParser()
    parser.add_argument('--model', default='yolov5m', type=str, help='The model to be compressed.')
    parser.add_argument('--dataset', default='COCO', type=str, choices=['VOC', 'COCO'], help='On which dataset the model is trained. VOC or COCO?')
    parser.add_argument('--compression', default='global', type=str, choices=['backbone', 'global'], help='To compress which part? backbone or all layers?')
    parser.add_argument('--prunemethod', default='L1', type=str, choices=['L1', 'L2'], help='The pruning algorithm for convolution layer.')
    parser.add_argument('--pruned', action='store_true', help='whether the checkpoint model have been pruned?')
    parser.add_argument('--round', default=0, type=int, help='the compression iteration of the network.')
    parser.add_argument('--topk', default=1.0, type=float, help='the filtering ratio P of target layers.')
    parser.add_argument('--exp', action='store_true', help='whether to compute the sensitivity in a sequential fashion')
    parser.add_argument('--initial_rate', default=0.05, type=float, help='the initial performance drop threshold for the first pruning layer')
    parser.add_argument('--initial_thres', default=5., type=float, help='the global performance drop threshold for the first pruning layer')
    parser.add_argument('--rate_slope', default=0., type=float, help='the adjustment slope of the initial masking ratio at each pruning iteration')
    parser.add_argument('--thres_slope', default=0., type=float, help='the adjustment slope of the initial performance drop threshold at each pruning iteration')
    parser.add_argument('--weights', type=str, default='yolov5s.pt', help='initial weights path')
    parser.add_argument('--pruned-model', type=str, default='', help='the path of the pruned model')
    parser.add_argument('--cfg', type=str, default='', help='model.yaml path')
    parser.add_argument('--data', type=str, default='data/coco128.yaml', help='dataset.yaml path')
    parser.add_argument('--hyp', type=str, default='data/hyps/hyp.scratch.yaml', help='hyperparameters path')
    parser.add_argument('--epochs', type=int, default=300)
    parser.add_argument('--batch-size', type=int, default=16, help='total batch size for all GPUs')
    parser.add_argument('--imgsz', '--img', '--img-size', type=int, default=640, help='train, val image size (pixels)')
    parser.add_argument('--rect', action='store_true', help='rectangular training')
    parser.add_argument('--resume', nargs='?', const=True, default=False, help='resume most recent training')
    parser.add_argument('--nosave', action='store_true', help='only save final checkpoint')
    parser.add_argument('--noval', action='store_true', help='only validate final epoch')
    parser.add_argument('--noautoanchor', action='store_true', help='disable autoanchor check')
    parser.add_argument('--evolve', type=int, nargs='?', const=300, help='evolve hyperparameters for x generations')
    parser.add_argument('--bucket', type=str, default='', help='gsutil bucket')
    parser.add_argument('--cache', type=str, nargs='?', const='ram', help='--cache images in "ram" (default) or "disk"')
    parser.add_argument('--image-weights', action='store_true', help='use weighted image selection for training')
    parser.add_argument('--device', default='', help='cuda device, i.e. 0 or 0,1,2,3 or cpu')
    parser.add_argument('--multi-scale', action='store_true', help='vary img-size +/- 50%%')
    parser.add_argument('--single-cls', action='store_true', help='train multi-class data as single-class')
    parser.add_argument('--adam', action='store_true', help='use torch.optim.Adam() optimizer')
    parser.add_argument('--sync-bn', action='store_true', help='use SyncBatchNorm, only available in DDP mode')
    parser.add_argument('--workers', type=int, default=0, help='maximum number of dataloader workers')
    parser.add_argument('--project', default='runs/train', help='save to project/name')
    parser.add_argument('--entity', default=None, help='W&B entity')
    parser.add_argument('--name', default='exp', help='save to project/name')
    parser.add_argument('--exist-ok', action='store_true', help='existing project/name ok, do not increment')
    parser.add_argument('--quad', action='store_true', help='quad dataloader')
    parser.add_argument('--linear-lr', action='store_true', help='linear LR')
    parser.add_argument('--label-smoothing', type=float, default=0.0, help='Label smoothing epsilon')
    parser.add_argument('--upload_dataset', action='store_true', help='Upload dataset as W&B artifact table')
    parser.add_argument('--bbox_interval', type=int, default=-1, help='Set bounding-box image logging interval for W&B')
    parser.add_argument('--save_period', type=int, default=-1, help='Log model after every "save_period" epoch')
    parser.add_argument('--artifact_alias', type=str, default="latest", help='version of dataset artifact to be used')
    parser.add_argument('--local_rank', type=int, default=-1, help='DDP parameter, do not modify')
    parser.add_argument('--freeze', type=int, default=0, help='Number of layers to freeze. backbone=10, all=24')
    parser.add_argument('--patience', type=int, default=100, help='EarlyStopping patience (epochs without improvement)')
    parser.add_argument('--noplots', action='store_true', help='save no plot files')
    opt = parser.parse_known_args()[0] if known else parser.parse_args()
    return opt


def main(opt, callbacks=Callbacks()):
    # Checks
    # set_logging(RANK)
    if RANK in [-1, 0]:
        print_args(opt)
        check_git_status()
        check_requirements(exclude=['thop'])

    # Resume
    if opt.resume and not opt.evolve:  # resume an interrupted run
        ckpt = opt.resume if isinstance(opt.resume, str) else get_latest_run()  # specified or most recent path
        assert os.path.isfile(ckpt), 'ERROR: --resume checkpoint does not exist'
        with open(Path(ckpt).parent.parent / 'opt.yaml') as f:
            opt = argparse.Namespace(**yaml.safe_load(f))  # replace
        opt.cfg, opt.weights, opt.resume = '', ckpt, True  # reinstate
        LOGGER.info(f'Resuming training from {ckpt}')
    else:
        opt.data, opt.cfg, opt.hyp = check_file(opt.data), check_yaml(opt.cfg), check_yaml(opt.hyp)  # check YAMLs
        assert len(opt.cfg) or len(opt.weights), 'either --cfg or --weights must be specified'
        if opt.evolve:
            opt.project = 'runs/evolve'
        opt.exist_ok, opt.resume = opt.resume or opt.pruned, False  # pass resume to exist_ok and disable resume
        opt.save_dir = str(increment_path(Path(opt.project) / opt.name, exist_ok=opt.exist_ok))

    # DDP mode
    device = select_device(opt.device, batch_size=opt.batch_size)
    if LOCAL_RANK != -1:
        from datetime import timedelta
        assert torch.cuda.device_count() > LOCAL_RANK, 'insufficient CUDA devices for DDP command'
        assert opt.batch_size % WORLD_SIZE == 0, '--batch-size must be multiple of CUDA device count'
        assert not opt.image_weights, '--image-weights argument is not compatible with DDP training'
        assert not opt.evolve, '--evolve argument is not compatible with DDP training'
        torch.cuda.set_device(LOCAL_RANK)
        device = torch.device('cuda', LOCAL_RANK)
        dist.init_process_group(backend="nccl" if dist.is_nccl_available() else "gloo")

    # Train
    if not opt.evolve:
        train(opt.hyp, opt, device, callbacks)
        if WORLD_SIZE > 1 and RANK == 0:
            LOGGER.info('Destroying process group... ')
            dist.destroy_process_group()


def run(**kwargs):
    # Usage: import train; train.run(data='coco128.yaml', imgsz=320, weights='yolov5m.pt')
    opt = parse_opt(True)
    for k, v in kwargs.items():
        setattr(opt, k, v)
    main(opt)


if __name__ == "__main__":
    opt = parse_opt()
    if opt.compression.lower() == 'backbone':
        opt.part = [f'model.{i}.' for i in range(6)]
    else:
        opt.part = ['model.0.',
                    'model.1.',
                    'model.2.',
                    'model.3.',
                    'model.4.',
                    'model.5.',
                    'model.6.',
                    'model.7.',
                    ]
    main(opt)
